Identification of a roseoflavin exporter in the roseoflavin producer Streptomyces davaonensis

玫瑰黄素生产者达沃链霉菌中玫瑰黄素输出者的鉴定

• 批准号: 461172511
• 负责人: Professor Dr. Matthias Mack
• 金额: --
• 依托单位: Institut für Technische Mikrobiologie (MIB)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/461172511?language=en
• 关键词: Identification; roseoflavin; exporter; producer; Streptomyces

The bacterium Streptomyces davaonensis produces the antibiotic roseoflavin in the stationary phase of growth. Roseoflavin is a structural riboflavin (vitamin B2) analog and acts as an antimetabolite. The Mack group was able to show that roseoflavin negatively affects FMN riboswitches as well as flavoproteins and thus the antibiotic has multiple cellular targets. The Mack group also has carried out fundamental work with regard to the biosynthetic pathway of roseoflavin. One important open question is at present how roseoflavin is exported from the producer cell. Our preliminary experiments clearly show that a yet unknown transporter is responsible for roseoflavin export as roseoflavin is found in the supernatant of cultures of the producer cell. Such an exporter protein must be highly specific to avoid export of essential riboflavin. Export of roseoflavin is important for the producer, otherwise the compound would not be able to inhibit growth of competing microorganisms in a natural environment. The objective of the present grant application is the identification of the roseoflavin exporter in S. davaonensis.Five different work packages describe experiments which should lead to the identification of the roseoflavin exporter. It is unclear at present whether a single protein or whether multiple proteins form this unique exporter. We plan to carry out systematic deletion experiments and co-expression experiments in different bacterial backgrounds to identify the roseoflavin exporter. In case these experiments fail we plan to carry out protein-protein interaction experiments. The hypothesis thereby is that the last enzyme of roseoflavin biosynthesis, RosA, which binds its reaction product roseoflavin very tightly, interacts with a membrane bound exporter. It is also possible that RosA interacts with a binding protein which then brings roseoflavin to the elusive exporter. Employing protein-protein interaction studies binding partners of RosA can be identified, which may help to identify components of the roseoflavin export system. In principle uptake systems – especially for riboflavin - are well described in bacteria. In contrast, only very few exporters are known which makes the present grant application especially interesting.

达文链霉菌（Streptomyces davaonensis）在生长的稳定期产生抗生素玫瑰黄素。玫瑰黄素是一种结构核黄素（维生素B2）类似物，并作为抗代谢药。Mack小组能够证明玫瑰黄素对FMN核糖开关以及黄素蛋白产生负面影响，因此抗生素具有多个细胞靶点。Mack小组还进行了关于玫瑰黄素生物合成途径的基础工作。目前一个重要的未决问题是玫瑰黄素如何从生产细胞中输出。我们的初步实验清楚地表明，一种未知的转运蛋白负责玫瑰黄素的输出，因为玫瑰黄素存在于生产细胞培养物的上清液中。这种输出蛋白必须是高度特异性的，以避免输出必需的核黄素。玫瑰黄素的出口对生产商来说很重要，否则该化合物将无法抑制自然环境中竞争微生物的生长。本研究申请的目的是鉴定S.五个不同的工作包描述了应该导致玫瑰黄素输出者的鉴定的实验。目前还不清楚是单个蛋白质还是多个蛋白质形成了这种独特的输出蛋白。我们计划在不同的细菌背景下进行系统的缺失实验和共表达实验，以确定玫瑰黄素输出蛋白。如果这些实验失败，我们计划进行蛋白质-蛋白质相互作用实验。因此，假设玫瑰黄素生物合成的最后一种酶RosA与其反应产物玫瑰黄素非常紧密地结合，与膜结合的输出蛋白相互作用。也有可能RosA与结合蛋白相互作用，然后将玫瑰黄素带到难以捉摸的出口商。采用蛋白质-蛋白质相互作用研究可以鉴定RosA的结合伴侣，这可能有助于鉴定玫瑰黄素输出系统的组分。原则上摄取系统-特别是核黄素-在细菌中有很好的描述。相比之下，只有很少的出口商是已知的，这使得目前的赠款申请特别有趣。